This invention relates to a device, more particularly an apparatus for retaining a disc obtained from a human cornea during cutting thereof to alter the surface of the corneal disc.
It is known in the field of ophthalmology that faulty vision can be corrected by altering the refractive power of an eye through transplanting a plane-parallel disc which has been obtained from a human cornea and provided with a surface that is shaped to a predetermined radius. An appliance for obtaining plane-parallel cornea discs is disclosed in West German Patent Publication No. 3,147,662. In conventional technology for altering the surface of a corneal disc, a plastic disc is turned on a lathe to form a recess having a radius corresponding to the outside radius of a disc obtained from a human cornea. Thereafter, the corneal disc is quickly frozen in the recess of the plastic disc and two surface curvatures are obtained by computer calculations of which one curvature is the inner optical zone and the other curvature is for the edge.
This process, known as keratomileusis, has a major disadvantage because of the requirement for complicated technological use of the lathe, the refrigeration technology, chemical pretreatment of the disc and chemical after treatment of the disc. The process involves about 70 steps and for optimum results, some of the steps must be carried out within a sharply defined period of time.